aabb calc fix in mesh, and a few compilation issues on osx (yosemite)

[colormotor]

No description provided.

[andy-thomason]

Many thanks for this.

The vmax issue is clearly a bug.
I would rather use plain old (int) casts (Call me old fashioned)
std::sqrt is not the same as sqrt as sqrt works on double precsion which is very slow sqrtf is more correct or include cmath header.

I'll submit another changelist for this.

[colormotor]

happy it helps!
Actually the other two modifications were just quick work-arounds because XCode was complaining (probably because my project settings are not correct).
I definitely prefer good old casts as well :)